3.73 or 4.11?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chevjayfsd · 06-01-2008, 07:19 PM

Hey guys,

We are going to get some new gears + posi. Right now we have 3.08 and no posi, and they are just dogs... My question though is should we go for 373s or 411s? It will see absolutely no highway driving, so that is not a concern, tranny is a th350...

Brad · 06-01-2008, 07:25 PM

If you're absolutely sure that you won't ever use it on the highway, then I'd go 4.11's!!

Otherwise, I'd go 3.73 for that occasional long distance trip.

69halfton · 06-01-2008, 07:27 PM

have to agree, gears make all the difference. if theres no highway, GO HIGHER

4.56!!

LONGHAIR · 06-01-2008, 07:42 PM

Ah.....that's lower

Shyguy · 06-01-2008, 08:27 PM

It depends on what kind of performance you want, also tire size can affect things.

I am running 3.73 gears with 31's, for my kind of driving it works out great. Most of my driving is in town and country roads.

Danny

Gulf Rat · 06-01-2008, 08:38 PM

I think you would like 3.55 with that turbo350 no overdrive, but thats my opinion.

Gulf Rat

shortbed70 · 06-01-2008, 10:23 PM

No highway 4.56 its fun.

whatnow123 · 06-01-2008, 10:29 PM

I've got 4.11's, posi and a very warm 350 and up to about 40 I have very limited traction with 30 inch tires that are 285's.

LUV2XCLR8 · 06-01-2008, 10:42 PM

Quote:

Originally Posted by Gulf Rat

I think you would like 3.55 with that turbo350 no overdrive, but thats my opinion.

Gulf Rat

I have 3.08 Posi on "Merlot" and I found a 3.42 on Evil Bay. I was going with
a 3.55 or 3.73 but with "GQ's" motor & a 700R I think I'll be happy with it

If it will NEVER see the highway then go

MPG is gonna suck anyways.

chevjayfsd · 06-01-2008, 10:50 PM

Tires are 275/60's = 28" tall... If your getting no traction with 30" tires... than what would that do with 28"!!! hahaa

Gulf Rat · 06-01-2008, 11:27 PM

Quote:

Originally Posted by LUV2XCLR8

I have 3.08 Posi on "Merlot" and I found a 3.42 on Evil Bay. I was going with
a 3.55 or 3.73 but with "GQ's" motor & a 700R I think I'll be happy with it

If it will NEVER see the highway then go

MPG is gonna suck anyways.

3.73 with a 700R4 is great pick, me using 3.73 with late model truck 5 speed.

Gulf Rat

redhead69 · 06-01-2008, 11:41 PM

I like my 3.73's. It really picked the truck up from the 3.08s and I can still go down the freeway @65 at right around 3k rpms. Im running a 28" tire. I drive it to the track and cross the finish line at around 4200rpms (1/4 mile) It would pick up a couple tenths with a lower (higher numerically) gear but driving the freeway would suck (gas that is). So my vote with no freeway driving would be the 4.11's Those would be a fun gear

LUV2XCLR8 · 06-02-2008, 01:23 AM

Quote:

Originally Posted by Gulf Rat

3.73 with a 700R4 is great pick, me using 3.73 with late model truck 5 speed.

Gulf Rat

Agreed, but we opted for the 3.42 since the "GQ" motor is going in front
of it. That way I can drive it long distances and get ok MPG. (Right now
in the 4wd w/ 3.08's and a 350 auto I only get 8, yes only 8 MPG)

Gulf Rat · 06-02-2008, 04:43 AM

I'm get 19 mpg if I drive 70mph, with a 350 mild cam Quadjet, no headers, daul exh. 3.73 gear.
Not bad for old 71 Chevy..

Gulf Rat

bigsnookmaster · 06-02-2008, 08:08 AM

3:73 is about perfect with your tire combination.What motor are you running,and what are your cam specs.Too much gear with not enough cam and you'll be running out of motor.I had a 4:56 gear years ago and it was fun for about two weeks.Went back to 3:73s and never regretted it.Just my .02

OrangeCrush1970 · 06-02-2008, 03:19 PM

You're looking at a new rear axle, if Im not mistaken 4.11's won't fit in a pumkin that 3.07's came stock in. Pumpkin is too small-

OrangeCrush1970 · 06-02-2008, 03:22 PM

Quote:

Originally Posted by Gulf Rat

I'm get 19 mpg if I drive 70mph, with a 350 mild cam Quadjet, no headers, daul exh. 3.73 gear.
Not bad for old 71 Chevy..

Gulf Rat

ARE YOU SERIOUS??? What's your secret? I get about 13mpg w/ a built 350 and 3.07's!!! Ahh...but Im running a TH350. Do you have a 4 or 5 speed tranny?

shortbed70 · 06-02-2008, 06:31 PM

WOW 19 out of a carbed 350 HOW????

LONGHAIR · 06-02-2008, 07:24 PM

Quote:

You're looking at a new rear axle, if Im not mistaken 4.11's won't fit in a pumkin that 3.07's came stock in. Pumpkin is too small-

It is not the entire axle housing that is different, just the "carrier". The part that the ring gear bolts onto. The difference is in the off-set of the flange. "High" gears (lower numerically) have more teeth on the pinion, making it larger in diameter. This forces the ring to be further off center.
Gear manifacturers compensate for this as the ratio gets lower. They make the ring gear thicker to match the smaller pinion, but only so far. Then you have to have a "low ratio" carrier, which has the ring flange closer to center.

Brad · 06-03-2008, 02:21 PM

Quote:

Originally Posted by shortbed70

WOW 19 out of a carbed 350 HOW????

I call

Especially at 70mph.

Gulf Rat · 06-03-2008, 04:46 PM

Quote:

Originally Posted by OrangeCrush1970

ARE YOU SERIOUS??? What's your secret? I get about 13mpg w/ a built 350 and 3.07's!!! Ahh...but Im running a TH350. Do you have a 4 or 5 speed tranny?

Secret, no real secret...5 speed trany, 275/60-17 tire thats 31" tall and keep your foot out of the 4b. Quadrejet's have always got me good gas mileage. Having the right combo of carb,cam,gearing is the secret. BTW that highway mileage, city around 15.

Gulf Rat

69swbman · 06-07-2008, 01:10 AM

i have 373 with 295/50/15 with a saginaw 4 spd and a pretty warm motor but with what i have in the rear (gears and tires) what would it make my gears?

**El Jay** · 06-07-2008, 02:16 AM

Quote:

Originally Posted by Gulf Rat

Secret, no real secret...5 speed trany, 275/60-17 tire thats 31" tall and keep your foot out of the 4b. Quadrejet's have always got me good gas mileage. Having the right combo of carb,cam,gearing is the secret. BTW that highway mileage, city around 15.

Gulf Rat

Just curious, have you had your speedo calibrated?

Rokcrln · 06-07-2008, 02:31 AM

Quote:

Originally Posted by LUV2XCLR8

Agreed, but we opted for the 3.42 since the "GQ" motor is going in front
of it. That way I can drive it long distances and get ok MPG. (Right now
in the 4wd w/ 3.08's and a 350 auto I only get 8, yes only 8 MPG)

This is just what I have in LowBuck and love it. The lower 1st gear in the 700R4 gives you that 3.73 take off feel and the 27% OD gives that 3.08 cruise. At 70MPH I run right about 2000 RPM and that is perfect for the vett LT1. It is one of the most versatile truck combo's I have ever had and I have had alot

Kevin
LFD Inc.

Gulf Rat · 06-07-2008, 10:01 AM

Quote:

Originally Posted by El Jay

Just curious, have you had your speedo calibrated?

Yep, changed the gear on the speedo cable checked it with GPS...would you like to come down and check the gas mileage yourself, come on down i'll have a cold one waiting.

Gulf Rat

06-01-2008, 07:19 PM	#1
chevjayfsd Project 7dos Join Date: Aug 2001 Location: Abilene, Texas Posts: 876	3.73 or 4.11?? Hey guys, We are going to get some new gears + posi. Right now we have 3.08 and no posi, and they are just dogs... My question though is should we go for 373s or 411s? It will see absolutely no highway driving, so that is not a concern, tranny is a th350... __________________ 7DOS - 1972 C-10 350/350 Porterbuilt/Accuair 20x8.5/20x10 Ride Low or Die PSSST - Yes it's bagged. 7dos build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=610290

06-01-2008, 07:25 PM	#2
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,672	Re: 3.73 or 4.11?? If you're absolutely sure that you won't ever use it on the highway, then I'd go 4.11's!! Otherwise, I'd go 3.73 for that occasional long distance trip. __________________ 1968 C-10 SWB, 5.7 Vortec/700R4/3.73 posi, Torch Red 1968 Camaro, 250/Powerglide, all original (No, I'm not gonna drop a 350 in it!...Jeez!) 2000 Honda VFR in the faster yellow! 2008 Husqvarna TE-610 1967 C-10 SWB 'Six Appeal'-Gone but not forgotten...

06-01-2008, 07:27 PM	#3
69halfton Registered User Join Date: Apr 2007 Location: King City, Ontario, Canada Posts: 974	Re: 3.73 or 4.11?? have to agree, gears make all the difference. if theres no highway, GO HIGHER 4.56!! __________________ - Jason If you can turn, Youre not going fast enough. Favorite caption: first car to 200 mph in the 1/4 mile, no parachute, drum brakes all the way around.. ..back when men were men.

06-01-2008, 07:42 PM	#4
LONGHAIR just can't cover up my redneck Join Date: May 2004 Location: Columbus OH Posts: 11,414	Re: 3.73 or 4.11?? Ah.....that's lower

06-01-2008, 08:27 PM	#5
Shyguy Junior Member Join Date: Dec 2006 Location: Southeast Missouri Posts: 2,436	Re: 3.73 or 4.11?? It depends on what kind of performance you want, also tire size can affect things. I am running 3.73 gears with 31's, for my kind of driving it works out great. Most of my driving is in town and country roads. Danny

06-01-2008, 08:38 PM	#6
Gulf Rat Registered User Join Date: Feb 2008 Location: Gulfport, MS Posts: 99	Re: 3.73 or 4.11?? I think you would like 3.55 with that turbo350 no overdrive, but thats my opinion. Gulf Rat

06-01-2008, 10:23 PM	#7
shortbed70 Registered User Join Date: Mar 2002 Location: Forney TX Posts: 4,512	Re: 3.73 or 4.11?? No highway 4.56 its fun. __________________ Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274

06-01-2008, 10:29 PM	#8
whatnow123 Registered User Join Date: Oct 2006 Location: Arizona Posts: 835	Re: 3.73 or 4.11?? I've got 4.11's, posi and a very warm 350 and up to about 40 I have very limited traction with 30 inch tires that are 285's. __________________ 67 Short Step, 355, 700R 4.11 posi rear, 4/6 drop Discs on all 4 corners. Build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=219094

06-01-2008, 10:50 PM	#10
chevjayfsd Project 7dos Join Date: Aug 2001 Location: Abilene, Texas Posts: 876	Re: 3.73 or 4.11?? Tires are 275/60's = 28" tall... If your getting no traction with 30" tires... than what would that do with 28"!!! hahaa __________________ 7DOS - 1972 C-10 350/350 Porterbuilt/Accuair 20x8.5/20x10 Ride Low or Die PSSST - Yes it's bagged. 7dos build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=610290

06-01-2008, 11:41 PM	#12
redhead69 fugedaboutit Join Date: Mar 2005 Location: Gresham, OR Posts: 832	Re: 3.73 or 4.11?? I like my 3.73's. It really picked the truck up from the 3.08s and I can still go down the freeway @65 at right around 3k rpms. Im running a 28" tire. I drive it to the track and cross the finish line at around 4200rpms (1/4 mile) It would pick up a couple tenths with a lower (higher numerically) gear but driving the freeway would suck (gas that is). So my vote with no freeway driving would be the 4.11's Those would be a fun gear __________________ Currently truckless

06-02-2008, 04:43 AM	#14
Gulf Rat Registered User Join Date: Feb 2008 Location: Gulfport, MS Posts: 99	Re: 3.73 or 4.11?? I'm get 19 mpg if I drive 70mph, with a 350 mild cam Quadjet, no headers, daul exh. 3.73 gear. Not bad for old 71 Chevy.. Gulf Rat

06-02-2008, 08:08 AM	#15
bigsnookmaster Registered User Join Date: Jan 2008 Location: St.Petersburg,Fl Posts: 1,267	Re: 3.73 or 4.11?? 3:73 is about perfect with your tire combination.What motor are you running,and what are your cam specs.Too much gear with not enough cam and you'll be running out of motor.I had a 4:56 gear years ago and it was fun for about two weeks.Went back to 3:73s and never regretted it.Just my .02 __________________ greg http://community.webshots.com/user/68406Stepside

06-02-2008, 03:19 PM	#16
OrangeCrush1970 Registered User Join Date: Jun 2007 Location: Smyrna, GA Posts: 709	Re: 3.73 or 4.11?? You're looking at a new rear axle, if Im not mistaken 4.11's won't fit in a pumkin that 3.07's came stock in. Pumpkin is too small- __________________ *Rottenwood Garage* 1970...71...72 C1500 aka Orange aka Sideshow Bob 540 BB Straub Roller Cam, AFR Magnums, XP 950, TKO 600 2 Tons of Fun

06-02-2008, 06:31 PM	#18
shortbed70 Registered User Join Date: Mar 2002 Location: Forney TX Posts: 4,512	Re: 3.73 or 4.11?? WOW 19 out of a carbed 350 HOW???? __________________ Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274

06-07-2008, 01:10 AM	#22
69swbman Registered User Join Date: Jun 2007 Location: peaster,tx Posts: 59	Re: 3.73 or 4.11?? i have 373 with 295/50/15 with a saginaw 4 spd and a pretty warm motor but with what i have in the rear (gears and tires) what would it make my gears?



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